The present invention relates to a maintenance method and system for a plasma processing apparatus having a vacuum processing chamber, and more particularly to maintenance during a restoring operation after completing the maintenance such as wet cleaning involving the opening of the vacuum processing chamber to the atmosphere.
Conventionally, the restoring operation after the maintenance involving the opening of a plasma processing apparatus to the atmosphere needs to check whether the air etc. leaks out of the vacuum processing chamber after starting vacuum evacuation, to check an attained pressure in the vacuum processing chamber, to check an amount of conveyed foreign substances and an amount of foreign substances produced by an electric discharge, and to check an etching rate or a film forming rate. Besides, because a judgment in each operation stage must be made based on experiences, it is necessary to have a person to operate or decide in each stage.
FIG. 7 shows an example of a processing procedure after wet cleaning according to a conventional method.
After completing a wet operation, the evacuation by a vacuum pump is started. Then, a leak check and an attained pressure check are performed in about two hours. If their results are NG (no good), the evacuation is performed again. And, if they are OK, a transfer, a gas discharge, a foreign substance check (that is, the checking of the increase of the number of foreign substances on a foreign substance checking wafer before and after QC (quality control such as the transfer processing)) (pre-measurement before QC, QC, post-measurement after QC) are performed. If they are OK, a dummy run (checking of the electric discharge using checking sample) is performed. Besides, an electric discharge foreign substance check (that is, the checking of the increase of the number of foreign substances on a foreign substance checking wafer before and after QC (discharge processing in this case)) (pre-measurement before QC, QC, post-measurement after QC) is performed, and if it is OK, a rate check (checking of the etching rate or the film forming rate) (pre-measurement before QC, QC, post-measurement after QC) is performed. If it is OK, processing of preproduction wafers (that is, the processing of an actual wafer before the production of the wafers) is started, and if it is OK, the wet operation is terminated. Then, processing of products is started.
As described above, the restoring operation after the maintenance work by the conventional method often requires the intervention of a person and the decision by a person. Therefore, the efficiency of work is poor, many people are required to start the operation and it takes lots of time to restore.
Accordingly, it is an object of the present invention to provide a maintenance method and system for a plasma processing apparatus which can omit complex works requiring the intervention of people and a judgment for pass or fail (suitability of processing) in each stage of restoration processing based on experiences and can realize saving of the manpower before starting the operation or shortening of restoration time.
One aspect of the invention is directed to a maintenance method after wet cleaning of a plasma processing apparatus which processes a specimen by plasma in a vacuum processing chamber, wherein:
when restoration processing after the wet cleaning of members configuring the vacuum processing chamber is performed with the vacuum processing chamber opened to the atmosphere for maintenance or the like,
it is automatically or semiautomatically judged whether the restoration processing is appropriate or not according to a predetermined optimum sequence inherent in the apparatus, and the next processing is started automatically or semiautomatically according to the results.
Another aspect of the invention is directed to a maintenance system for a plasma processing apparatus, which is provided with a vacuum processing chamber, a vacuum evacuation section, a plasma generating gas supply section, a plasma generating section, and a specimen stage on which a wafer to be processed in the vacuum processing chamber is placed, which comprises an operation circuit for performing a sequence for a restoring operation after wet cleaning, a storage section for storing measured data, a plurality of detection sensors for collecting measured data values from the operating plasma processing apparatus, an I/O section for determining prescribed values, and a comparison/decision circuit for comparing the prescribed values with the data stored in the storage section.
According to the present invention, the complex works requiring the intervention of people are previously combined as an optimum sequence inherent in the apparatus, a check program is semiautomatically or automatically activated according to the sequence, it is judged whether each stage of the restoration processing has passed or failed (whether the processing is appropriate or not), and according to the results, the processing can be proceeded semiautomatically or automatically to the next stage and processing, so that the manpower before starting the operation can be saved or the restoration time can be shortened.